Magnetic Resonance Imaging–Visible Perivascular Spaces in Basal Ganglia Predict Cognitive Decline in Parkinson's Disease

BACKGROUND: Growing evidence suggests an association between imaging biomarkers of small vessel disease and future cognitive decline in Parkinson's disease (PD). Recently, magnetic resonance imaging-visible perivascular space (PVS) has been considered as an imaging biomarker of small vessel disease, but its effect on cognitive decline in PD is yet to be investigated. OBJECTIVE: The objective of this study was to evaluate whether PVS can independently predict cognitive decline in PD. METHODS: A total of 271 PD patients were divided into 106 patients with intact cognition (PD-IC) and 165 patients with mild cognitive impairment (PD-MCI). After a mean follow-up of 5.0 ± 2.3 years, 18 PD-IC patients showed cognitive decline to PD-MCI and 34 PD-MCI patients showed cognitive decline to dementia. PVS was rated in the basal ganglia (BG) and centrum semiovale using a 4-point visual scale and then classified as high (score ≥ 2) or low (score < 2) according to severity. Lacunes and white matter hyperintensity severity were also assessed. Independent risk factors for cognitive decline were investigated using multivariable logistic regression analysis. RESULTS: In all patients, higher BG-PVS and white matter hyperintensity severity, higher levodopa-equivalent dose, hypertension, and lower Mini-Mental State Examination score were independent positive predictors of future cognitive decline. In the PD-IC subgroup, higher BG-PVS severity, hypertension, and more severe depressive symptoms were predictors of cognitive conversion. In the PD-MCI subgroup, higher BG-PVS and white matter hyperintensity severity, and lower Mini-Mental State Examination score were predictors of cognitive decline. CONCLUSIONS: BG-PVS may be a useful imaging marker for predicting cognitive decline in PD. © 2019 International Parkinson and Movement Disorder Society.